Aqui alguns cursos interessantes de graça:

Cursos Gratuitos

http://www.torneseumprogramador.com.br/
https://jornadadodev.com.br/
https://www.htmlecsspro.com/
https://www.cursoemvideo.com/
http://ead.ti.srt.ifsp.edu.br/
https://moodle.ifrs.edu.br/
https://www.origamid.com/curso/css-flexbox/
https://www.youtube.com/watch?v=nl-Is79eyD8&list=PL9rc_FjKlX3-K25DZVcNlsVDItg9OlZiW
https://www.youtube.com/watch?v=hKXOVD2Yrj8&t=6s&ab_channel=Origamid
https://rocketseat.com.br/discover
https://station.cataline.io/basecamp
http://loiane.training/
https://balta.io/comecar
https://materiais.estudarfora.org.br/cc50-harvard/

Bootcamps gratuitos

https://www.42sp.org.br/
https://www.hiringcoders.com.br/
https://dio.me/